Sporadic Vibration when braking - NOT warped rotors
 

1998 V70 T5 Wagon.

Sometimes when braking the entire car will violently shudder like I'm driving over rumble strips. it comes on slowly but becomes all encompassing if you continue pressing the brakes. If you pump it it will go away. It seems to originate from the rear as well.

If you're in California you'll know the vibration I'm talking about. On the side of the road the concrete is formed so when you drive over it you're whole car will shudder violently.

It is not warped rotors as the rears were replaced, the fronts are fine and the pedal does not pulse at any speed and the brakes work fine otherwise. warped rotors will vibrate every time, they will pulse the pedal as well. THis is entirely different and sporadic.

any ideas? has anyone had a stuck caliper before? it almost feels like this is the case.

drzaeis,

A few questions to help understand:
-does the frequency of the vibration vary with the speed of the car?
-does the vibration occur only when braking hard or from a high speed?
-does the steering wheel vibrate at all?

Bob

Bob,

Thanks for responding.

the speed of the car does not effect the vibration - it can happen when going 5 mph or 40 mph, makes no difference
it happens actually at lighter brake pressures more frequently
the steering wheel does not vibrate -

I've already replaced the rear rotors and pads on all 4 wheels -

I'll tell you all what I did find though. The right rear caliper had one stuck piston, torn caliper piston boot, and a bad wheel bearing. I'm suspecting excess heat in that area coupled with the torn boot was making the piston stick. As of Wed, Nov 28 we rebuilt the caliper, and replaced the bearing with a Timkin bearing,$200!! BTW for the bearing. Initial test drive was ok but this has been sporadic so I will update everyone after a bit of driving but any other input is appreciated.

Right good,

My 2003 V70 had a bad right rear wheel bearing just over a year ago. Funny thing is it took months before I realized there was a howling sound so bad passengers in the car could barely talk.

My daily commute to work is 6 miles driving 35 miles per hour. It wasn't until I took a 4 hour trip on the highway that the howling gave me a pounding headache. No vibration (that I could feel) but, it did ruin the right rear tire with severe cupping wear.

Bob

hate to jinx myself but I think the vibration was the stuck piston on the rear caliper. Seems to be all better.

Also if anyone needs a new caliper it's way cheaper to rebuild it yourself than buy a new one. Super easy job also. The rebuild kit is $7

Maybe that's what it was but I would ck the rest of the suspension components for wear/looseness. Have a feeling you'll find a sloppy ball joint or tie rod.

Did that clear up the vibrations?

I was experiencing the same thing, with a constant ticking as if the cv axles were going out, and I removed the drive shaft to eliminate that possibility, only to find it was the problem!

It was pretty bad, like your saying, and I don't see how the stuck caliper would do it............

It was absolutely the stuck caliper. What was happening was only one piston was pushing out of the caliper, thus hitting the rotor only on one side, creating a tremendous imbalance. We had already replaced the rotors to no avail and frankly it didn't feel like rotors as the problem was sporadic.

Thanks for posting the follow up. It's always helpful to learn how these things get resolved. I had a hard pulsing from the rear brakes when braking hard or from hi speed. Quite certain it was not warped rotors.

I re-bedded the brakes and all is well. I suspect it was extra brake pad material sticking to the rotors from when I set the E brake. Not setting the E brake so much any more, at least not on flat level ground any more.

Bob